Gestating sows are commonly placed in gestation crates within confinement buildings which permits each sow to be cared for and fed individual diets. The gestation crates limit the exercise available to the sow which is confined to the crate for much of the gestation period of approximately 114 days. Advantages exist in allowing the sows to exist in loose housing as distinguished from the confinement of gestation crates. Loose housing permits greater exercise for the sow during gestation, and permits the sows to live in social groups. However, loose housing makes it more difficult for each sow to be supplied the required feed ration. It is important to control the weight of the sow during gestation to maximize productivity and to increase sow longevity in the herd.
In response to the need for improved individual feeding of group-housed sows, electronic sow feeding systems began to appear. These feeding systems allow individualized feeding of a set amount of gestation feed to each sow in combination with loose housing. In an electronic sow feeding system, a sow is identified by an electronic transponder or responder on a collar or ear tag as she enters a feeding stall. A transponder emits a signal that is read by an antenna. A responder waits for a signal from an antenna and then responds with the sow's data. After the sow has been identified by the system, a gate closes behind her to keep other sows from entering the feed station. A prescribed amount of feed is provided for the sow to eat in the privacy of the feeding stall. After eating, the sow exits out the stall returning to the rest of the group and the station is ready for another sow. A computer system keeps track of the sow visits to the feed station, and the feed consumed. Electronic sow feeding systems were developed from systems used to feed dairy cattle as individuals. These sow feeding systems demonstrate relatively new technology and are not in extensive use within the U.S.A.
One characteristic of these systems is that limited amounts of feed are supplied to each sow daily. This characteristic leads to sows who are not satiated and are aggressive toward pen mates even though their nutrient needs have been met. By feeding a bulky ration which meets their nutrient requirements great satiety can be achieved. The use of weight gain to control nutrient intake permits a more welfare-friendly feeding system and can utilize lower value feed ingredients.
It is therefore an object of this invention to provide a quasi ad-libitum electronic feeding system which will provide a sow her proper ration as determined by measurements of average daily gains while meeting her need for satiety through use of bulk ingredients.
It is a further object of this invention to provide a quasi ad-libitum electronic feeding system which will permit a plurality of gestating sows to be electronically measured (weight and average daily gain) and electronically controlled for access to one of two predetermined rations.
It is a further object of this invention to provide a quasi ad-libitum electronic feeding system which will permit a group of gestation sows to be continuously monitored by computer technology to assimilate and store data on each sow's growth rate, dietary intake and other production parameters.
These and other objects will be apparent to those skilled in the art.